This invention relates to nonwoven abrasive articles and methods of making same. More particularly, this invention relates to nonwoven abrasive articles having a rebulkable nonwoven web with a continuous sheet-like abrasive coating and methods of making same.
The use of nonwoven abrasive products for abrading, polishing, cleaning, conditioning, and/or decorating the surfaces of metal, wood, plastics, ceramics, and the like is known. Nonwoven abrasive products may be formed of randomly disposed staple fibers which are bonded together at points of contact with a binder and may optionally contain abrasive particles. Typically, the staple fibers have been crimped and are laid into lofty open webs by equipment such as a "Rando-Webber" machine (available from Rando Machine Corporation, Macedon, N.Y.). One commercial embodiment of such an abrasive article is available under the trade designation "SCOTCH-BRITE" (available from Minnesota Mining and Manufacturing Company of St. Paul, Minn.).
Nonwoven abrasive articles of this type can be prepared by the method disclosed in U.S. Pat. No. 2,958,593 (Hoover et al.). Hoover et al. reports such nonwoven webs as comprising many interlaced randomly disposed flexible durable tough organic fibers. The fibers of the nonwoven web are firmly bonded together at points where they intersect and contact one another by globules of an organic binder, thereby forming a three-dimensionally integrated structure. Distributed throughout the nonwoven web are abrasive particles which are bonded to the fibers by the binder. These abrasive articles may be described as being "open" in that the interior portion of the nonwoven web is open to the surface being abraded. An open construction allows for swarf from the workpiece to be taken up by the nonwoven web.
Rebulkable nonwoven scouring articles having an abrasive-free interior are reported in PCT published application 94/04738 (Heyer et al.). The abrasive particles are concentrated in approximately the outer one-third of the nonwoven web by applying the abrasive particles to the rebulkable nonwoven web while the web is in a densified state. The densified nonwoven web is then rebulked to provide an open nonwoven abrasive article.
Although nonwoven abrasive articles have found numerous uses, producers of nonwoven abrasive articles desire ways to provide abrasive articles suitable for new applications. An area of particular need is automotive body repair. An abrasive article is needed to quickly level and blend coated (i.e., painted) repair areas to match the surrounding original coatings without leaving unacceptable scratches.